36 resultados para frequency scaling factors

em Repositório Institucional UNESP - Universidade Estadual Paulista "Julio de Mesquita Filho"


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Preterm infants in neonatal intensive care units frequently receive red blood cells (RBC) transfusions due to the anemia of prematurity. A number of variables related to gestational age, severity of illness and transfusion practices adopted in the neonatal unit where the neonate was born may contribute to the prescription of RBC transfusions. This study aimed to analyse the frequency and factors associated with RBC transfusions in very-low-birth-weight preterm infants. A prospective cohort of 4283 preterm infants (gestational age: 29.9 ± 2.9 weeks; birth weight: 1084 ± 275 g) carried out at 16 university hospitals in Brazil between January 2009 and December 2011 was analysed. Factors associated with RBC transfusions were evaluated using univariate and multiple logistic regression analysis. A total of 2208 (51.6%) infants received RBC transfusions (variation per neonatal unit: 34.1% to 66.4%). RBC transfusions were significantly associated with gestational age (OR: -1.098; 95%CI: -1.12 to -1.04), SNAPPE II score (1.01; 1.00-1.02), apnea (1.69; 1.34-2.14), pulmonary hemorrhage (2.65; 1.74-4.031), need for oxygen at 28 days of life (1.56; 1.17-2.08), clinical sepsis (3.22; 2.55-4.05), necrotising enterocolitis (3.80; 2.26-6.41), grades III/IV intraventricular hemorrhage (1.64; 1.05-2.58), mechanical ventilation (2.27; 1.74-2.97), use of umbilical catheter (1.86; 1.35-2.57), parenteral nutrition (2.06; 1.27-3.33), >60 days of hospitalization (5.29; 4.02-6.95) and the neonatal unit where the neonate was born. The frequency of RBC transfusions varied among neonatal intensive care units. Even after adjusting for adverse health conditions and therapeutic interventions, the neonatal unit continued to influence transfusion practices in very-low birth-weight infants.

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Soil aggregation is an index of soil structure measured by mean weight diameter (MWD) or scaling factors often interpreted as fragmentation fractal dimensions (D-f). However, the MWD provides a biased estimate of soil aggregation due to spurious correlations among aggregate-size fractions and scale-dependency. The scale-invariant D-f is based on weak assumptions to allow particle counts and sensitive to the selection of the fractal domain, and may frequently exceed a value of 3, implying that D-f is a biased estimate of aggregation. Aggregation indices based on mass may be computed without bias using compositional analysis techniques. Our objective was to elaborate compositional indices of soil aggregation and to compare them to MWD and D-f using a published dataset describing the effect of 7 cropping systems on aggregation. Six aggregate-size fractions were arranged into a sequence of D-1 balances of building blocks that portray the process of soil aggregation. Isometric log-ratios (ilrs) are scale-invariant and orthogonal log contrasts or balances that possess the Euclidean geometry necessary to compute a distance between any two aggregation states, known as the Aitchison distance (A(x,y)). Close correlations (r>0.98) were observed between MWD, D-f, and the ilr when contrasting large and small aggregate sizes. Several unbiased embedded ilrs can characterize the heterogeneous nature of soil aggregates and be related to soil properties or functions. Soil bulk density and penetrater resistance were closely related to A(x,y) with reference to bare fallow. The A(x,y) is easy to implement as unbiased index of soil aggregation using standard sieving methods and may allow comparisons between studies. (C) 2012 Elsevier B.V. All rights reserved.

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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

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Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

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The human buccal micronucleus cytome assay (BMCyt) is one of the most widely used techniques to measure genetic damage in human population studies. Reducing protocol variability, assessing the role of confounders, and estimating a range of reference values are research priorities that will be addressed by the HUMNXL, collaborative study. The HUMNXL, project evaluates the impact of host factors, occupation, life-style, disease status, and protocol features on the occurrence of MN in exfoliated buccal cells. In addition, the study will provide a range of reference values for all cytome endpoints. A database of 5424 subjects with buccal MN values obtained from 30 laboratories worldwide was compiled and analyzed to investigate the influence of several conditions affecting MN frequency. Random effects models were mostly used to investigate MN predictors. The estimated spontaneous MN frequency was 0.74 parts per thousand (95% CI 0.52-1.05). Only staining among technical features influenced MN frequency, with an abnormal increase for non-DNA-specific stains. No effect of gender was evident, while the trend for age was highly significant (p < 0.001). Most occupational exposures and a diagnosis of cancer significantly increased MN and other endpoints frequencies. MN frequency increased in heavy smoking (>= 40 cig/day. FR = 1.37:95% CI 1.03-.82) and decreased with daily fruit consumption (FR = 0.68; 95% CI 0.50-0.91). The results of the HUMNXL, project identified priorities for validation studies, increased the basic knowledge of the assay, and contributed to the creation of a laboratory network which in perspective may allow the evaluation of disease risk associated with MN frequency. (C) 2011 Elsevier B.V. All rights reserved.

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Toxoplasmosis is a worldwide zoonosis caused by Toxoplasma gondii that can infect a large variety of animals, including humans. The present study aimed to evaluate the frequency of anti-T. gondii antibodies in dogs from a peripheral district of Botucatu and to establish the association among some epidemiological variables in order to evaluate risk factors for toxoplasmosis infection. Serum samples from dogs were screened using an indirect fluorescent antibody (IFA) test. Anti-T. gondii antibody prevalence was 56%. The highest titer was 1024 (1.79%) and the most frequent titers were 16 (57.14%) and 64 (33.93%). The chi-square (X-2) test revealed significant association among variables such as dog access to street, ingestion of raw meat and presence of synantropic animals in the domestic environment. These results demonstrate that toxoplasmosis is present in dogs from Jardim Santa Elisa district.

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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

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Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

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We present an analytic study of the finite size effects in sine-Gordon model, based on the semi-classical quantization of an appropriate kink background defined on a cylindrical geometry. The quasi-periodic kink is realized as an elliptic function with its real period related to the size of the system. The stability equation for the small quantum fluctuations around this classical background is of Lame type and the corresponding energy eigenvalues are selected inside the allowed bands by imposing periodic boundary conditions. We derive analytical expressions for the ground state and excited states scaling functions, which provide an explicit description of the flow between the IR and UV regimes of the model. Finally, the semiclassical form factors and two-point functions of the basic field and of the energy operator are obtained, completing the semiclassical quantization of the sine-Gordon model on the cylinder. (C) 2004 Elsevier B.V. All rights reserved.

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Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

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OBJECTIVE: To assess biochemical, anthropometric, and dietary variables considered risk factors for coronary artery disease. METHODS: Using anthropometrics, dietary allowance, and blood biochemistry, we assessed 84 patients [54 males (mean age of 55± 8 years) and 30 females (mean age of 57±7 years)], who had severe ( > or =70% coronary artery obstruction) and nonsevere forms of coronary artery disease determined by cardiac catheterization. The severe form of the disease prevailed in 70% of the males and 64% of the females, and a high frequency of familial antecedents (92% ' 88%) and history of acute myocardial infarction (80% ' 70%) were observed. Smoking predominated among males (65%) and diabetes mellitus among females (43%). RESULTS: Males and females had body mass index and body fat above the normal values. Females with nonsevere lesions had HDL > 35 mg/dL, and this constituted a discriminating intergroup indicator. Regardless of the severity of the disease, hyperglycemia and hypertriglyceridemia were found among females, and cholesterolemia > 200 mg/dL in both sexes, but only males had LDL fraction > 160 mg/dL and homocysteine > 11.7 mmol/L. The male dietary allowance was inadequate in nutrients for homocysteine metabolism and in nutrients with an antioxidant action, such as the vitamins B6, C, and folate. Individuals of both sexes had a higher lipid and cholesterol intake and an inadequate consumption of fiber. The diet was classified as high-protein, high-fat, and low-carbohydrate. CONCLUSION: The alterations found had no association with the severity of lesions, indicating the need for more effective nutritional intervention.